There have been proposed and sometimes implemented in the past, at least in experimental installations, systems, apparatuses and processes for cultivating microorganisms particularly microalgae to produce useful by-products such as lipids potentially useful as a source of fuels. There have been two broad approaches to such microorganism cultivation on a large scale, the first using large open ponds, raceways, vats or the like in which the microorganisms such as microalgae are grown and subsequently harvested, and the second involving closed vessels or passages in which the microorganisms are moved in a nutrient medium while being exposed to incident radiation, either solar or artificial radiation, to promote the growth and propagation of the microorganism culture. The open systems are particularly vulnerable to contamination by other organisms which can either predate the desired species or become more dominant in the population of microorganisms thus degrading the productive output and commercial viability or, at the very least, requiring continual measures to inhibit or remove the contaminating population. The closed system designs have been far too costly to be commercially viable for commercial fuel production. Both have tended to use land with high alternative use value.
In most of the above systems, the aqueous nutrient medium carrying the microorganism culture has been agitated or moved at flow velocities to nutrify the medium with CO2 to maintain turbulent conditions for the purposes of preventing or minimising settling of microorganisms, coagulation or flocculating of microorganism clusters limiting optimum growth within the culture, and to continuously mix nutrients and microorganisms and to remove waste products so as to ensure that all receive adequate nutrition, space and insolation to optimise growth and reproduction. However, such turbulent flow can require substantial energy inputs to pump the nutrient and microorganism soup and maintain the required turbulence.
There have been many other limitations and drawbacks of particular large scale microorganism cultivating and processing systems which will be mentioned in this specification where relevant in the particular context of the description of parts of the present applicant's method, apparatus and system.
The above and following references, including references in the Appendix of the present specification, to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art.
Throughout the specification, including the claims, the present applicant's overall system, process, and apparatus, many individual aspects of which are not in themselves essential and may be omitted or varied in particular implementations of the applicant's system, will be referred to as the “Winwick system”, “Winwick process”, “Winwick apparatus”, etc. This is for convenient reference but it is to be understood that the particular aspect of the system, method or apparatus being described, or indeed the references to the system, method and apparatus as a whole are not to be construed as being necessarily essential to the present invention.